Fuse link expelling means



W. O. SCHULTZ ET AL FUSE LINK EXPELLING MEANS Aug. 9 1938.

Filed March 10, 1937 2 Sheets-Sheet 1 INVENTORS.

ATTORNEY.

w. o. SCHULTZ ET AL 2,126,216

FUSE LINK EXPELLING MEANS v Aug. 9, 1938.

2 Sheets-Sheet 2 Filed March 10, 193mg i u, M

ATTORNEY.

Patented Aug. 9, 1938 UNITED STATES PATENT, OFFICE FUSE LINK EXPELLING DEANS Application March ill, 1937, Serial No. 130,054 13 tllalms. it'll. 200-127) This invention relates to improvements in i'use link-expelling means for expulsion fuses.

It is an object of this invention to provide for expulsion fuses, link-expelling means comprising a spring-actuated lever adapted to withdraw the fuse link from the tube in a path extending lougitudinolly from the end thereof.

Another object of this invention is to provide a spring-actuated lever for expelling a fuse limit m from a cartridge and adapted to clampinglv eugage the fuse link while the latter is under tension and to release the fuse link after the link has been. withdrawn from the cartridge.

A further object is to provide for standard expulsion fuses, fuse link-expelling means provlding the above-noted features and adapted for detachable connection with the fuse, thereby ore= venting old expulsion fuses from becoming ohsolete.

2o still further object is to provide a fuse linkexpelling device in which the expelling lever is movable radially on its pivot against the action of its biasing spring, thereby to permit a fuse limb; to be engaged. clampingly by the lC-EVEL' after 25 the level" has been moved to llnls-teuslonlug post-- time.

to 3, inclusive, are suhstahtiahv iden tical with those shown in the copemddi'ig' application of William G. E chuita, Number so ire-cost, filed March. it, war, for Fuse liulz throw= 1 out devices.

the drawings: Fig. is a side elevation illustrating a preferred form of this invention.

35 Fig. 2 is a fragmentary view in side elevation of the device shown in Fig. 1 after it has oper= Fig. 8 is a lower end view of the device shown in Fla. 1.

to is a fragmentary view in side elevation illustrating a modified form of tl'us invention.

Fig. 5 is a fragmentary view in side elevation illustrating the device shown in Fig. t after it o operated.

4,5 611s a view oi" the fuse link-commons mechanism before it is removed from the tube and taken from the left-hand side relative to Fig. 5.

Lille parts are identified by the some refer ence characters throughout the several views.

so In all of the expulsion fuses shown in the drawlogs, the fuse comprises a cartridge 6 having an upper contact ferrule 2, closure cap it, lower con tact ferrule l spaced from the lower open end of the tube and provided with a. depending clamping arm 5, and a clamping screw or bolt 6 and a fuse link i disposed in the tube for electrically connecting the upper contact ferrule 2 and the lower contact ferrule i. The clamping arm 5 is provided with a clamping lug 8 which is slotted at 9 in a vertical direction and longitudinally 5 relative to the cartridge l. The clamping lug 8 is also provided with a threaded recess ex tending toward the base of the slot 9 and adapted to receive the threaded end of the clamping loolt 10 in the preferred form of the throwout device illustrated in Figs. 1 to 3, inclusive, a hollow sleet hood Hills provided with a supporting arm it having vertically extending portion (12 positioned in the slot 9 and iemcvably secured therein by means of the clamping bolt the sleet hood it is also provided with a recessed apron or til extending below the arm it and with a clamping law i l extending iii a horizontal di- 'lou latertdlv from the lower margin of the 243 t. As shown, this jaw M is provided vdth an cuate clamping lace upon its under side. The shirt i3 is provided with a pivot pin to extend-- to the interior of the shirt for supporting the lever as will hereinafter appear. 2

The tlru'owout lever 06 comprises a link-tensiohiog it provided with. a link engaging finger G8, a spring-engaging arm it provided with sorlue reoeiving aperture it, a plvot en gaging, arm. 2i extending to the interior of the W l8 and provided with an elongated slot slldahlv receiving the pin and a clamping low cooperating with the clamping jawll for securing the link i therein as will hereafter appear. As shown, the clamping 223 is pr vlded with an arcuate clamping surface offset from the arcuate clamping surface on the clamplhgz i l. The link-engaging arm is provided with a reinforcing rib on the lower side thereof.

The throvvout lever ltis biased to the'posllo tioii shown in Fig. 2 by means of a coil spring engaged at one end in the aperture ill of the lever and at its other end 26 with the bottom of the hollow or recess Ell in the hood ill. Thus the spring is extended into the hood and is protested against sleet formation which would tend. to hamper the contractile action of the spring.' The throwout lever it naturally assumes the position shown in Fig. 2. When the fuse link 7! is placed in the tube l as shown in Fig. 1, it will he passed beneath the finger l8 of the lever E6 to hold the lever in the position shown and will then be placed between the clamping jaws l4 and 23. In order to facilitate the placing of the fuse link between the clamping jaws l4 and 23,.the

slot 22 in the arm 2i of the throwout lever I6 is provided. This slot 22 permits the throwout lever iii to be moved downwardly on the pin I5 relative to Fig. 2 for the purpose of separating the clamping jaws I4 and 23. When these jaws have been separated sufficiently, the link may then be placed between them and upon release of the lever I6, the spring will clamp the jaws to the link 1.

It will be observed that the spring-engaging arm I9 on the lever I5 is extended in a horizontal direction to the right relative to Fig. 1. This extended portion ISA serves as a means for manually moving the lever I6 to separate the jaws I4 and 23. It will be further observed that the link-engaging finger I8 on the lever I6 is directly beneath the cartridge I. Consequenthr, when .the jaws I4 and 23 are separated by pressing down on the portion ISA, the finger I8 will contact the end of the cartridge and serve as a pivot point while the link 1 is being inserted between the jaws.

Although the finger I8 is not shown in contact with the lower end of the cartridge, nevertheless, it will be obvious that its position relative to the cartridge when in link-stressing position, will be a matter of choice when the link is mounted in the cartridge.

Fig. 2 illustrates the portion ISA on the lever I6 in contact with the lower margin of the hood l8, thereby serving as a stop defining the final position of the lever after the link 1 has been withdrawn from the cartridge.

The device illustrated in Figs. 1 to 3, inclusive,

' operates as follows: Assuming that the fuse link 1 has been tensioned as illustrated in Fig. 1, and that an overload has destroyed the upper end of the fuse link (not shown), the spring 25 will cause the lever to rotate about the pin I5 and thereby move the fuse link in a path extending downwardly and arcuately from the lower end of the tube I. When the lever I3 has moved a given distance in the path indicated, the jaws l4 and 23 will be separated sufficiently to permit the link to drop from the structure, thereby clearly indicating that the circuit through the fuse has been opened.

A modified form of the invention disclosed herein is shown in Figs. 4 to 6, inclusive. Fig. 4 discloses the device in operative position relative to the tube I, the clamping bolt 6 and the fuse leader-'1. The supporting arm 28 is bent to provide a vertical section 38 and upper and lower angularly extending portions 30A and 383, the upper end of the upper portion 30A being provided with an aperture 23A adapted to receive the upper end of the spring 29 and the lower end of the lower portion 303 being formed into two spaced supporting fingers 3I-3I, each finger being provided with vertically extending elongated slots 32 as shown in Fig. 4. A pivot pin 33 extends between the fingers 3I-3I and is slidable in the elongated slot 32.

. A throwout lever 34 is pivotally mounted on pin 33 and is provided with a link-engaging finger 38 adapted to receive the leader 1 and hold it in alignment with the throwout lever 34. Formed as an integral part of the throwout lever, is a resilient finger 38A extending in an arched path above the broad section 31A of the throwout lever 34. The throwout lever or channel member 34 has tapered sides 34A, one of which is cut away to provide a slot 35A. The bottom of the channel member 38 is slotted at 33 to provide a clamping finger 38A and a bridge 33A. The bridge section 33A is provided with an aperture 38 adapted to receive the lower portion of spring 29. The sides 34A of the lever are connected by a pivot pin 33 extending laterally from the sides and through the slots 32 in the fingers 3I--3I.

The operative relation of the fuse leader 1 and the throwout lever 34 is clearly shown in Fig. 4. The leader 1 extending from the bottom of the fuse tube I is passed under the link-engaging finger 35, passed up through the opening 35A and between the two pivot-supporting legs 3|, this last passageway being enlarged by the downward movement of the throwout lever in the radial slots 32, thus providing more clearance between the resilient finger 36A and the contact face 31. The tension spring 29 mounted between the two apertures 29A and 38 provides a clamping action on the leader 1 between the contact surface 31 and finger 36A andtransmits a throwout action at the link-engaging finger end on the leader 1.

After a predetermined overload has acted on the fuse link, the throwout device throws the leader 1 downwardly free from the tube while the throwout lever describes an arcuate path downward and away from the end of the tube I. When this action has taken place, the device is in the position shown in Fig. 5. As the lever 34 moves away from. the tube end about the pivot pin 33, the clamping action of the finger 35A against the contact face 31 is destroyed, which permits the leader to drop from the structure, thereby providing a clear indication that the circuit through the fuse has been opened.

The device shown in Figs. 4 to 6, inclusive, is modified from that shown in Figs. 1. to 3, inclusive, in that the radial slot 32 is placed on the supporting fingers 3i of the supporting arm 28, while the radial slot 22 in Figs. 1 to 3, inclusive, is placed in the pivot-engaging arm 2i of the throwout lever l5. Another difference is noted in the exposure of the tension spring 28 in Figs. 4 and 5 and the attachment of the upper end of the spring with the upper portion of the supporting arm 28 different from the encased spring 25 shown in Figs. 1 and 2 and the attachment of its upper end with the hood III.

From the foregoing it will be apparent that a fuse link throwout device for expulsion fuses has been provided which pulls the link in an axial direction relative to and exteriorly of the tube, thereby producing a minimum flexing of the link as it leaves the tube. It will also be seen that the throwout device provides a positive release of the link after the latter is removed from the tube and thereby permits the link to drop from the fuse structure. Furthermore, the means for releasing the link provides a simple, movable clamp for the protruding end of the link, enabling easy assembly of the link in operative position.

Obviously, the throwout device herein disclosed can be cheaply manufactured and provides suitable protection of the movable parts from sleet and damage.

In addition to the principal objects of the invention heretofore disclosed, it will be apparent that we have provided a throwout device in which the lever biasing spring 25 (Figs. 1 and 2) and 23 (Figs. 4 and 5), as well as the throwout lever 18 (Figs. 1 and 2) and 34 (Figs. 4 and 5) are not subjected to destructive full line currents because fuse links tensioned thereby are held in direct electrical connection with the pivot support.

We have also provided a throwout device in which the throwout lever assumes a predetermined position after it has withdrawn a fuse link and in which the clamping action of the throwout lever is not dependent upon the thickness of the material or the kind of material of the lever. That is, the lever may be made very sturdy and need not be made of metal, although such may be preferred.

Another feature which will be apparent from the foregoing disclosure is in the novel arrangement of the lever supporting pivot means whereby the projecting ends of the fuse links may be positioned between the clamping jaws regardless of the transverse dimension of the link and without changing the pointof application of the throwout lever.

We claim:

1. A fuse link throwout device for expulsion fuses, said device comprising a supporting member having a link-clamping pbrtion, a throwout lever pivotally mounted on the support for tensioning said link and having a link-clamping portion cooperatively related to said clamping portion on said support, and a spring secured at one end to said support and at the other end to said lever, said clamping portions being upon a side of the pivotal mounting of said lever opposite to that on which said spring is secured to said lever, whereby said spring holds said clamping portions operative while said lever tensions said link and moves said lever from clamping position after said fuse link is severed.

2. The combination with an expulsion tube and a fuse link extending therefrom, of a fuse link throwout device supported by said tube and comprising a support secured to the tube and having a link-clamping portion, a throwout lever pivotally mounted on the support and having a clamping portion operatively related to said clamping portion on said support, and a spring having one end engaged with the support and the other end engaged with said lever, said clamping portions being upon a side of the pivotal mounting of said lever opposite to that on which said spring is secured to said lever, said lever being engaged with said fuse link to pull said link from said tube and clamping the extending portion of said link to said support, said spring holding said clamping portions operative while said lever tensions said link and biasing said lever to pull said link from said tube and cause separation of said clamping portions when said fuse link is severed, whereby to release said fuse link from clamping position between said lever and said support.

3. The combination with. an expulsion tube and a fuse link extending therefrom, of a fuse link-expelling device comprising a support mounted on said tube, a throwout lever pivotally mounted on said support, the pivotal mounting of said lever being movable in a radial direction relative to the pivot axis, a spring coacting between said support and throwout lever, said lever engaging said fuse link and being biased by said spring to pull said fuse link from said tube, said lever clampingly engaging said fuse link to said support and being biased'to clamping position by said spring while said lever is engaged with said link.

4. A fuse link throwout device for expulsion fuses, said device comprising a support adapted for attachment to a fuse cartridge, a throwout lever pivotally mounted intermediate its ends on said support to provide a fuse link-engaging arm on one side of the pivot and a lever-actuating arm on the other side of said pivot, and a spring engaged at one endwith said support and at the other end with said lever-actuating arm, said lever and support having cooperating clamping portions for securing a fuse link thereto when said link-engaging arm is engaged with said fuse link. 1

5. A fuse link throwout device for expulsion fuses, said device comprising a support adapted for attachment to a fuse cartridge, a throwout lever pivotally mounted intermediate its ends on said support to provide a fuse link-engaging arm on one side of, the pivot and a lever-actuating arm on the other side of said pivot, and a spring engaged at one end with said support and at the other end with said lever-actuating arm, said lever and support having cooperating clamping portions for securing a fuse link thereto when said link-engaging arm is engaged with said fuse link, the pivotal mounting of said lever being movable in a direction laterally of the pivot axis to facilitate clamping engagement of said fuse' link.

6. A fuse link throwout device for expulsion fuses, said device comprising a support adapted for attachment to a fuse cartridge, a throwout lever pivotally mounted intermediate its ends on said support to provide a fuse link-engaging arm and a lever-actuating arm, a spring connected at one end with said support and at the other end with said lever-actuating arm, and means for clampingly engaging a fuse link when said link-engaging arm is engaged therewith, said means beingupon a side of the pivotal mounting of said lever opposite to that on which said leveractuating arm is positioned.

7. A fuse link throwout device for expulsion fuses, said device comprising a support adapted for attachment to a fuse cartridge, a throwout lever pivotally mounted intermediate its ends on said support to provide a fuse link-engaging arm and a lever-actuating arm, a spring connected at one end with said support and at the other end with said lever-actuating arm, and means for clampingly engaging a fuse link when said link-engaging arm is engaged therewith, said means being upon a side of the pivotal mounting of said lever opposite to that on which said leveractuating arm is positioned, the pivotal mountingof said lever being movable in a direction laterally of the pivot axis.

8. In combination with a fuse cartridge having an open end and a fuse link projecting therefrom, a fuse link throwout device comprising a support secured to said cartridge, a throwout said link-engaging arm being movable in an are extending tangentially from the open end of said tube, thereby to pull said link from said tube with a minimum flexing thereof, and means for clamping the projecting portion of said link t said support.

9. In combination with a fuse cartridge having an open end and a fuse link projeting therefrom, a fuse link throwout device corn-- prising a support secured to said cartridge, a throwout lever pivotally mounted intermediate its ends on said support to provide a link-en aging arm to engage with said link and a lever-engaging arm, a spring secured at one end to said support and at the other end to said lever-engaging arm and biasing said lever 75 to pull said link from said tube, said link-engaging arm being movable in an are extending tangentially from the open end of said tube, thereby to pull said link from said'tube with a minimum flexing thereof, and means for clamping the projecting portion of said link to said support, the pivotal mounting of said lever being movable in a direction laterally of the pivot axis, thereby to facilitate clamping of said link.

10. In combination with a fuse cartridge having an open end and a fuse link projecting therefrom, a fuse link throwout device comprising a support secured to said cartridge, a throwout lever pivotally mounted intermediate its ends on said support to provide a link-engaging arm to engage .with said link and a lever-engaging arm, and a spring secured at one end to said support and at the other end to said lever-engaging arm and biasing said lever to pull said link from said tube, said link-engaging arm being movable in an are extending tangentially from the open end of said tube, thereby to pull said link from said tube with a minimum flexing thereof, said support and lever having cooperating clamping portions for clamping the projecting end of said link therebetween.

11. In combination with a fuse cartridge having an open end and a fuse link projecting therefrom, a fuse link throwout device comprising a support secured to said cartridge, a throwout lever pivotally mounted intermediate its ends on said support to provide a link-enaging arm to engage with said link and a lever-engaging arm, and a spring secured at one end to said support and at the other end to said lever-engaging arm and biasing said lever to pull said link from said tube, said link-engaging arm being movable in an are extending tangentially from the open end of said tube, thereby to pull said link from said tube with a minimum flexing thereof, said support and lever having cooperating clamping portions for clamping the projecting end of said link therebetween, the pivotal mounting of said lever being movable in a direction laterally of the pivot axis and biased against said movement by said spring, thereby to facilitate clamping of said link and to thereafter hold said link in clamped position.

12. In combination with a fuse cartridge having an open end and a fuse link projecting therefrom, a fuse link throwout device comprising a support secured to said cartridge, a throwout lever pivotally mounted intermediate its ends on said support to provide a link-engaging arm to engage with said link and a leverengaging arm, and a spring secured at one end to said support and at the other end to said lever-engaging arm and biasing said lever to pull said link from said time, said link-engaging arm being movable in an are extending tangentially from the open end of said tube, thereby to pull said link from said tube with a minimum flexing thereof, said support and lever having cooperating clamping portions for clamping the projecting end of said link therebetween, the pivotal mounting of said lever'being movable in a direction laterally of the pivot axis and biased against said movement by said spring,

thereby to facilitate clamping of said link and to thereafter hold said link in clamped position, said clamping portion automatically releasing said link when the latter is pulled from said cartridge.

13. The combination with a fuse cartridge having an open end and a fuse link projecting therefrom, of a throwout device comprising a supporting arm secured to said cartridge, a

throwout lever pivotally mounted on said arm and having a link-tensioning position, the pivotal connection between said arm and lever being disposed in a plane normal to and adjacent the end of said cartridge, said lever being slidable on said pivot in a direction paralleling said :1.

cartridge, a clamping jaw on said arm and a cooperating clamping jaw on said lever and beneath the other jaw, said jaws being substantially normal to the sliding path of said lever and relatively below said pivot, said jaws clampingly engaging said fuse link and extending laterally relative to said arm and lever, said lever engaging and tensioning said fuse link adjacent said open end, and a spring coacting between said arm and lever to hold said jaws in clamping relation and urging said lever to pull said link from said tube. 

